In-line mixing systems for fluids normally utilize baffles or partitions within a conduit to cause the fluid material to be agitated and kneaded as it passes through the conduit.
Commonly, in-line mixing systems are utilized in the mixing of epoxies, resins, foams and other compositions which set and harden, and it is important that such mixing systems be quickly purged and cleaned of the mixed material before setting occurs. Even with the practice of good cleaning and maintenance procedures, it is not uncommon for the material to harden within the mixing apparatus often necessitating discarding of the apparatus and replacement in view of the difficulty to clean. Various systems have been proposed for minimizing problems arising with respect to the cleaning and purging of in-line mixing systems, but present apparatus have not fully solved the problems.
It is an object of the invention to provide a linear in-line mixing system utilizing a plurality of disposable, low cost, mixing elements removably located within a conduit whereby the elements may be readily removed from the conduit even if the mixed material has hardened therein.
Another object of the invention is to provide a linear in-line mixing system wherein superior mixing of a fluid material flowing through a plurality of elements is achieved in a relatively short axial flow path, and the resistance to material flow is not excessively high.
An additional object of the invention is to provide a linear in-line mixing system utilizing a plurality of low cost, disposable mixing elements located in end-to-end abutting relationship within a conduit, each element including a passage having a set of helical vanes spiralling in opposite directions about the element's longitudinal axis.
Yet another object of the invention is to provide an in-line linear mixing system utilizing a plurality of disposable elements located within a conduit in abutting end-to-end relationship wherein the elements are interlocked to produce a desired orientation between adjacent elements and prevent relative rotational displacement.
In the practice of the invention a plurality of inexpensive, annular, molded, cylindrical elements are located in abutting end-to-end relationship within a conduit. The elements each include a passage, and the passages of adjacent elements are aligned with each other concentric to the conduit. Each element includes a pair of helical vanes, the vanes spiralling in opposite directions about the associated element's longitudinal axis. The vanes include linear leading and trailing edges disposed at right angles to the element axis wherein the edges aid in the mixing and agitation of material flowing therethrough, and the vanes within a common element are rotationally offset 90.degree. with respect to each other.
Opposite ends of the elements include an axially extending recess and complementary projection wherein the projection of one element is received within the recess of the adjacent engaged element preventing relative rotational displacement of the elements and maintaing a predetermined rotational orientation therebetween.
The diameter of the elements is slightly less than the inner diameter of the conduits with which they are associated, whereby the elements may be easily removed from the associated conduit, and the elements are of such configuration as to cooperate with the end fittings of the associated conduit wherein the end fittings maintain the elements within the conduit during operation.